Treatment system and treatment apparatus

ABSTRACT

A treatment system is disclosed, which has a treatment apparatus for performing a predetermined treatment for a planar workpiece contained in a carrier, and an first air-tight carrier storage chamber for storing the carrier. The treatment apparatus may also have an air-tight second carrier storage chamber. An inert gas supply and an exhaust means are connected to each of the treatment apparatus, the first carrier storage chamber, and the second carrier storage chamber. A valve device is provided for the inert gas supply and exhaust means.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a treatment system for performing atreatment for planar workpieces slouch as semiconductor substrates andLCD substrates and a treatment apparatus for the same.

2. Description of the Related Art

In semiconductor production process and LCD production process, acontainer called a carrier, cassette, or the like is used to transfer aplurality workpieces (such as semiconductor substrates and LCDsubstrates) at a time so as to improve productivity.

For example, in a semiconductor production plant, a plurality of (forexample, 25) semiconductor wafers which have been lithography treatedare contained in a carrier. The carrier is transferred by a transferrobot to a heat treatment apparatus. In a conventional heat treatmentapparatus, semiconductor wafers are transferred from a carrier to awafer boat. A large number of wafers (for example, 100 wafers) areplaced on the wafer boat at a time. The wafers on the wafer boat areloaded in a furnace. In the furnace, the wafers are oxidized, diffused,or heat-treated (for example, by CVD method). The wafers which have beenheat-treated are transferred from the wafer boat to a carrier.Thereafter, the carrier is transferred to the transfer robot.

Thus, in this heat treatment apparatus, 100 wafers (which are containedin a total of four carriers) are heat-treated at a time. Since thetransfer robot transfers one or two carriers at a time, however,carriers which contain wafers which have not been heat-treated arestored on a shelf disposed in the heat treatment apparatus. In a heattreatment system having a plurality of heat treatment apparatuses, acarrier storage chamber which is called a carrier stocker simply calledstocker is additionally provided. This carrier storage chamber storesseveral dozens of carriers.

Conventionally, clean air is blown to carriers stored on the carrierstorage shelf or in the carrier storage chamber so as to preventparticles from adhering to the wafers. However, in the vicinity of thecarrier storage shelf and in the carrier storage chamber, molecules ofO₂ and H₂ O in air cause the surfaces of wafers to be oxidized, therebyforming unnecessary natural oxide films. For example, in CVD process fordepositing a metal layer, if a natural oxide film is formed on a surfaceof a wafer, the film forming characteristics of metal layers depositedthereon adversely fluctuate. Thus, it is undesirable to allow carriersor wafers which are being temporarily stored to be oxidized. Sincecarriers may be stored in the carrier storage chamber for long periods,such natural oxide films are very likely to form.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a treatment system forpreventing workpieces contained in carriers or transferred therewithfrom being adversely oxidized or deteriorated.

A first aspect of the present invention is a treatment system,comprising a treatment apparatus for performing a predeterminedtreatment for a planar workpiece contained in a carrier, a firstair-tight carrier storage chamber for storing the carrier, a gas supplymeans for supplying an inert gas to the first carrier storage chamber,and a gas exhaust means for exhausting a gas from the first carrierstorage chamber.

A second aspect of the present invention is a treatment system,comprising a treatment apparatus for performing a predeterminedtreatment for a planar workpiece contained in a carrier, a first carrierstorage chamber for storing the carrier, and a transfer means disposedbetween the treatment apparatus and the first carrier storage chamberwhich is adapted for transferring the carrier therebetween, wherein thetransfer means is disposed in an air-tight transfer chamber, and whereina gas supply means for supplying an inert gas to the transfer chamberand an exhaust means for exhausting a gas from the transfer chamber areconnected to the transfer chamber.

A third aspect of the present invention is a treatment apparatus forperforming a predetermined treatment for a planar workpiece contained ina carrier, the treatment apparatus comprising a treatment chamber, afurnace disposed in the treatment chamber and adapted heat-treating theworkpiece contained in the carrier, a second air-tight carrier storagechamber disposed in the treatment chamber and adapted for storing thecarrier, a gas supply means for supplying an inert gas to the secondcarrier storage chamber, and an exhaust means for exhausting a gas fromthe second carrier storage chamber.

A fourth aspect of the present invention is a treatment apparatus forperforming a predetermined treatment on a planar workpiece contained ina carrier, the treatment apparatus comprising an air-tight treatmentchamber, a furnace disposed in the treatment chamber and adapted forheat-treating the workpiece contained in the carrier, a second carrierstorage chamber disposed in the treatment chamber and adapted forstoring the carrier, a gas supply means for supplying an inert gas tothe air-tight treatment chamber, and an exhaust means for exhausting agas from the treatment chamber.

According to the first aspect of the present invention, the firstcarrier storage chamber is airtightly constructed, and an inert gas issupplied to the first carrier storage chamber by the inert gas supplymeans. Atmospheric gases such as O₂ gas and H₂ O gas in the firstcarrier storage chamber are exhausted along with the inert gas throughthe gas exhaust means from the first carrier storage chamber. Thus, aworkpiece contained in a carrier stored in the first carrier storagechamber can be protected from being oxidized or deteriorated.

According to the second aspect of the present invention, the transferchamber is airtightly constructed, and an inert gas is supplied by theinert gas supply means to the transfer chamber. Atmospheric gases suchas O₂ gas and H₂ O gas in the transfer chamber are exhausted along withthe inert gas through the gas exhaust means from the transfer chamber.Thus, a workpiece contained in a carrier which is being transferred inthe transfer chamber can be protected from being oxidized ordeteriorated.

According to the third aspect of the present invention, the secondcarrier storage chamber is airtightly constructed, and an inert gas issupplied to the second carrier storage chamber by the inert gas supplymeans. Atmospheric gases such as O₂ gas and H₂ O gas in the secondcarrier storage chamber are exhausted along with the inert gas throughthe gas exhaust means from the second carrier storage chamber. Thus, aworkpiece contained in a carrier stored in the second carrier storagechamber can be protected from being oxidized or deteriorated.

According to the fourth aspect of the present invention, the treatmentchamber is airtightly constructed, and an inert gas is supplied by theinert gas supply means to the treatment chamber. Atmospheric gases suchas O₂ gas and H₂ O gas in the treatment chamber are exhausted along withthe inert gas through the gas exhaust means from the treatment chamber.Thus, a workpiece contained in a carrier which is being transferred inthe treatment chamber can be protected from being oxidized ordeteriorated.

These and other objects, features and advantages of the presentinvention will become more apparent in light of the following detaileddescription of a best mode embodiment thereof, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view schematically showing a heat treatmentsystem according to an embodiment of the present invention;

FIG. 2 is a perspective view showing an I/O station of the embodiment;

FIG. 3 is a sectional view showing a carrier swinging mechanism of theI/O station of the embodiment;

FIG. 4 is a plan view showing a rotation drive portion of the carrierswinging mechanism of FIG. 3;

FIG. 5 is a side view showing a carrier liner of the embodiment;

FIG. 6 is a side view showing a state where arms of the carrier liner ofthe embodiment is contracted to some extent;

FIG. 7 is a plan view showing both an engagement portion of the carrierand a holding portion of the carrier liner of the embodiment;

FIG. 8 is a side view schematically showing peripheral portions of atransfer path of a clean room mechanism of the embodiment;

FIG. 9 is a perspective view showing an example of a carrier storageportion of a stocker of the embodiment;

FIG. 10 is a perspective view showing a state where a door of thecarrier storage portion of the embodiment is open;

FIG. 11 is a side view schematically showing the relationship of thecarrier storage portions when one door thereof is open;

FIG. 12 is a side view schematically showing an example of the heattreatment apparatus of the embodiment;

FIG. 13 is a block diagram showing an example of a control system of theembodiment; and

FIG. 14 is a detailed side view showing an open/close device eachdisposed on a gas supply pipe and an exhaust pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Next, with reference to the accompanying drawings, an embodiment of thepresent invention will be described.

FIG. 1 is a perspective view schematically showing a heat treatmentsystem according to an embodiment of the present invention. As shown inthe figure, the heat treatment system comprises a plurality of uprighttype heat treatment apparatuses (for example, four upright type heattreatment apparatuses 10, 12, 14, and 16), a stocker 18, and an I/O(incoming/outgoing) station 20, a carrier liner 22, and a transfer path24. The four upright type heat treatment apparatuses 10, 12, 14, and 16are disposed in line. The stocker 18 and the I/O station 20 are disposedin series with the upright type heat treatment apparatuses 10, 12, 14,and 16. The carrier liner 22 travels on the transfer path 24. Thetransfer path 24 is disposed straight along the front of each of theheat treatment apparatuses 10, 12, 14, and 16, the stocker 18, and theI/O station 20.

In the heat treatment system, a plurality of (for example 25)semiconductor wafers W, which are workpieces, are contained in a carrierCR and transferred therewith. In the heat treatment system. the carrierliner 22 transfers two carriers CR among the heat treatment apparatuses10, 12, 14, and 16, the stocker 18, and the I/O station 20 at a time.The I/O station 20 functions as a carrier entrance/exit of the entiresystem.

The I/O station 20 has a carrier transfer unit 26 which transfers one ortwo carriers CR between an external transfer robot (not shown) and thecarrier liner 22. The external transfer robot travels near to a firstcarrier load/unload position 20a at a side edge portion of the I/Ostation 20. In the first carrier load/unload position 20a, the transferrobot loads or unloads one or two carriers CR to or from the carriertransfer unit 26. At this time, the carrier CR is loaded or unloadedwith the orientation of arrow P of FIG. 1. In other words, flangeportions FL at the top of the carrier CR are positioned in parallel withthe arm of the robot. Below the first carrier load/unload position 20a,an optical communication portion 21 which exchanges opticalcommunication signals or other means with the transfer robot.

The carrier liner 22 travels near to a second carrier load/unloadposition 20b on the front of the I/O station 20. In the second carrierload/unload position 20b, the carrier liner 22 loads or unloads one ortwo carriers CR to or from the carrier transfer unit 26 at a time. Atthis time, one or two carriers CR are loaded or unloaded with thedirection of arrow Q of FIG. 1. In other words, the upper flangeportions FL of each carrier CR are positioned in parallel with thelongitudinal direction of each arm of the carrier liner 22.

In the I/O station 20, the carrier transfer unit 26 transfers eachcarrier CR on paths between the first and second carrier load/unloadpositions 20a and 20b (these paths are denoted by dotted lines J1 andJ2). In addition, the carrier transfer unit 26 rotates each carrier CRby around 90°, thereby changing its orientation from the arrow P to thearrow Q or vice versa. Thus, the robot transfers a carrier CR which isoriented in the direction of the arrow P to the carrier transfer unit 26at the first carrier load/unload position 20. Thereafter, the carriertransfer unit 26 changes the orientations of the carriers CR to thedirection of the arrow Q and then transfers them to the carrier liner 22at the second carrier load/unload position 20b. In contrast, the carrierliner 22 transfers one or two carriers CR which are oriented in thedirection of the arrow Q to the carrier transfer unit 26 in the secondcarrier load/unload position 20b. Thereafter, the carrier transfer unit26 changes the orientation of the carrier CR to the direction of thearrow P and then transfers it to the transfer robot in the first carrierload/unload position 20a.

As described above, in the heat treatment system, the I/O station 20 isdisposed apart from the heat treatment apparatuses 10, 12, 14, and 16.Carriers CR are transferred between the external transfer robot and thecarrier transfer unit 26 in the first carrier load/unload position 20aat the side portion of the I/O station 20. In addition, the carriers CRare transferred between the carrier transfer unit 26 and the carrierliner 22 in the second carrier load/unload position 20b on the front ofthe I/O station 20. Between the first and second carrier load/unloadpositions 20a and 20b, the orientation of each carrier CR is rotated byaround 90°. Thus, it is not necessary to cause the external transferrobot to directly access to the heat treatment apparatuses 10, 12, 14,and 16. Therefore, since the operation of the transfer robot can besimply controlled, the transfer efficiency of the carriers CR isimproved. In addition, dust produced by the transfer robot does notaffect the heat treatment apparatuses 10, 12, 14, and 16.

FIG. 2 shows a practical example of the carrier transfer unit 26. Asshown in the figure, the carrier transfer unit 26 comprises a pair ofcarrier transfer portions 30 and 46. The carrier transfer portions 30and 46 each transfers a carrier CR.

The first carrier transfer portion 30 comprises a carrier table 32, aturn table 34, and a carriage 36. The carrier table 32 holds a carrierCR. The turn table 34 rotates the carrier CR. The carriage 36 allows thecarrier CR to travel in an X direction (see FIG. 2). The carriage 36 istravelled by a pulse motor 42 through a ball screw 40 along a guide rod44 disposed between the first and second carrier load/unload positions20a and 20b. The ball screw 40 extends in the X direction on a baseplate 38. The base plate 38 is fixedly supported by a support member(not shown).

The second carrier transfer portion 46 comprises a carrier table 48, aturn table 50, an X carriage 52, and a Y carriage 54. The table 48 holdsa carrier CR. The turn table 50 rotates the orientation of the carrierCR. The X carriage 52 allows the carrier CR to travel in the Xdirection. The Y carriage 54 allows the carrier CR to travel in a Ydirection. The X carriage 52 is travelled by a motor 60 through a ballscrew 58 along an X guide rod 62 in the X direction between the firstand second carrier load/unload positions 20a and 20b. The ball screw 58extends in the X direction on the base plate 56. The Y carriage istravelled by a pulse motor 66 through a ball screw 64 along a Y guiderod 68 in the Y direction. The ball screw 64 extends in the Y directionon the X carriage 52. Since the Y carriage 54 travels in the Y directionin the vicinity of the first carrier load/unload position 20a, thesecond carrier transfer portion 46 does not collide with the firstcarrier transfer portion 30.

Thus, in the carrier transfer unit 26, the first carrier transferportion 30 transfers a carrier CR on a straight path in the X direction,while the second carrier transfer portion 46 transfers another carrierCR on an L-letter shaped path in the X and Y directions. As a result,the carrier transfer unit 26 can simultaneously transfer two carriers CRbetween the first and second carrier load/unload positions 20a and 20bwithout their interference.

FIGS. 3 and 4 show the carrier table 32 and the turn table 34 of thefirst carrier transfer portion 30. As shown in FIG. 3, a pair ofprotruding portions 32a are disposed on the upper surface of the carriertable 32. Lower portions on both the sides of a carrier CR are held bythe protruding portions 32a. The lower surface of the carrier table 32is connected to a turn table 34 by a plurality of support rods 33. Theturn table 34 is rotatably supported by a cylindrically bottomed tablehousing 34b through a ring-shaped bearing 34a. A center portion of thelower surface of the turn table 34 is connected to an edge portion of apiston rod 34f through a rotation shaft 34c and a joint 34d. Thecylinder 34e is rotatably disposed about a rotation shaft 34h through ahorizontal support rod 34g. As shown in FIG. 4, when the cylinder 34ecauses the piston rod 34f to extend, the rotation shaft 34c and the turntable 34b rotate counterclockwise through the joint 34d. In contrast,when the piston rod 34f retreats, the rotation shaft 34c and the turntable 34b rotate clockwise through the joint 34d. This constructionapplies to the carrier table 48 and the turn table 50 of the secondcarrier transfer portion 46.

Next, the construction and operation of the carrier liner 22 accordingto the embodiment will be described. As shown in FIG. 1, the carrierliner 22 horizontally travels on the transfer path 24 routed straightfrom end to end of the system along the front portion of each of theheat treatment apparatuses 10, 12, 14, and 16, the stocker 18, and theI/O station 20. When the carrier liner 22 loads carriers CR at the I/Ostation 20, it transfers the carriers CR to the stocker 18, and the heattreatment apparatuses 10, 12, 14, and 16 corresponding to an instructionreceived from a host computer (which will be described later). In theheat treatment system according to this embodiment, the carrier liner 22is of a double-deck type where a pair of carrier liners 22 areintegrally disposed each of which transfer one carrier CR. The carrierliner 22 can transfer two carriers CR at a time.

FIGS. 5 to 7 show a practical example of the construction of theprincipal portions of the carrier liner 22. In FIGS. 5 and 6, a baseplate 76 is horizontally disposed at an end of a piston rod 74 whichvertically extends from a cylinder 72. A vertical support plate 78 isvertically disposed on the base plate 76. An arm support portion 82 isrotatably mounted on the vertical support plate 78 through a rotationshaft 80.

A first arm 84 is slidably mounted on the upper surface of the armsupport portion 82 through a slide portion 86 in the longitudinaldirection thereof. A second arm 88 is slidably mounted on the uppersurface of the first arm 84 through a slide portion 90 in thelongitudinal direction thereof.

A pair of stopper members 82a for stopping the first arm 84 are securedto both ends of the upper surface of the arm support portion 82. A pairof stopper members 84a for stopping the second arm 88 are secured toboth ends of the upper surface of the first arm 84. The second arm 88comprises an arm base plate 88a, a pair of carrier holding portions 88b,and an arm open/close device 88c. The arm base plate 88a is secured tothe slide portion 90. The carrier holding portions 88b hold the carrierCR. The arm open/close device 88c opens and closes the carrier holdingportions 88b.

Three fixed pulleys 92, 94, and 96 are mounted on one side of the armsupport portion 82. The fixed pulley 92 is disposed closest to the baseplate 76 and connected to a rotation drive shaft 102. Four fixed pulleys104, 98, 100, and 106 are mounted on one side of the second arm 88. Oneendless drive belt BL is wound on the seven pulleys 92, 94, 96, 98, 106,104, 100, and 92 in this order. The drive belt BL is secured to the armbase plate 88a of the second arm 88 through a clamp member 108.

In the state shown in FIG. 5, when a drive motor (not shown) rotates thedrive pulley 92 through the rotation drive shaft 102 clockwise, thedrive belt BL runs in the direction of arrow C0 (see FIG. 5). Thus, thesecond arm 88 moves in the direction of arrow B0 (contracts) through theclamp member 108. When an end of the arm base plate 88a of the secondarm 88 comes in contact with the stopper 84a on the base plate 76 sideof the first arm 84, the movement (contraction) of the second arm 88stops as shown in FIG. 6. When the drive pulley 92 is further rotatedclockwise, the second arm 88 and the first arm 84 move in the directionof arrow B0 (contracts) until the end of the first arm 84 comes in tocontact with the stopper 82a on the rear end side of the arm supportportion 82. When the drive pulley 92 is rotated counterclockwise, thereverse of the above-described operation is performed. In other words,when the drive pulley 92 is rotated counterclockwise, the first andsecond arms 84 and 88 move in the direction of arrow B1 (extend) andthen only the second arm 88 moves in the same direction.

As described above, in the carrier liner 22 according to the embodiment,the first and second arms 84 and 88 extend and contract with two steps.Thus, even if the transfer path 24 is narrow, by contacting the arms 84and 88, carriers CR can be quickly transferred without changing theirorientations. In addition, even if a carrier load/unload position ofeach of the heat treatment apparatuses 10, 12, 14, and 16, the stocker18, and the I/O station 20 is secluded from the carrier liner 22, byextending the arms 84 and 88, carriers CR can be easily loaded andunloaded.

Moreover, in the carrier liner 22 according to this embodiment, by acarrier inclining mechanism, a carrier CR can be inclined correspondingto the inclined direction of wafers W therein. An air cylinder 110 isvertically disposed at an edge portion of the base plate 76. A pistonrod 112 of the air cylinder 110 is connected to the lower surface of anedge portion of the arm support portion 82 through a joint 114.

In the condition where the flange portions FL of a carrier CR are placedin flat position (namely, the wafers W in the carrier CR are placed inupright position), when the piston rod 112 is extended, the arm supportportion 82 and the first and second arms 84 and 88 rotate about therotation shaft 80 counterclockwise. Thus, the forward end side of thecarrier holding portion 88b of the second arm 88 lowers and thereby thecarrier CR inclines downward. At this time, the wafers W in the carrierCR incline in such a way that the surface under treatment of each of thewafers W faces upward. By contracting the piston rod 112, theabove-described operation is reversely performed. In other words, theflange portions FL of the carrier CR is placed in flat position. Thus,the wafers W in the carrier CR are placed in upright position. When thepiston rod 112 is further contracted, the arm support portion 82 and thefirst and second arms 84 and 88 rotate about the rotation shaft 80clockwise. Thus, the forward end side of the carrier holding portion 88bof the second arm 88 rises and thereby the carrier CR inclines upward.At this time, the wafers W in the carrier CR incline in such a way thatthe surface under treatment of each of the wafers W face downward. Thewafers W are preferably inclined in such a way that the surface undertreatment thereof faces downward to some extent. This is because whenthe wafers W are inclined in such a way, they can prevent adhesion ofparticles. The vertical support plate 78 has two types of stoppers 116and 118. The stopper 116 stops the clockwise rotation of a bottomportion of the arm support portion 82 at a predetermined angle. On theother hand, the stopper 118 stops the counterclockwise rotation of thebottom portion of the arm support portion 82 at a predetermined angle.

As shown in FIG. 7, shoulder portions CRa are defined in the vicinity ofboth edges of the flange portions FL of the carrier CR. Thus, a total offour shoulder portions CRa are defined on the carrier CR. Protrudingportions 88e are defined at the carrier holding portion 88b of thesecond arm 88 corresponding to the shoulder portions CRa. When thecarrier liner 22 holds a carrier CR, the protruding portions 88e on thecarrier holding portions 88b are engaged with the corresponding shoulderportions CRa of the carrier CR. Thus, even if the carrier CR is inclineddownward, it does not drop from the arm.

As a result, in the carrier liner 22 according to this embodiment, acarrier CR can be inclined in a predetermined range of angles in thedirection where the wafers W are inclined. Thus, in the carrier liner22, the following carrier transfer operation can be performed.

The carrier liner 22 causes the first and second arms 84 and 88 toextend at the I/O station 20 so as to receive a carrier CR. The aircylinder 72 causes the carrier CR to rise to a predetermined height. Theair cylinder 110 causes the carrier CR to incline downward by forexample 5°. The carrier liner 22 causes the first and second arms 84 and88 to contract. In this condition, the carrier liner 22 horizontallytravels on the transfer path 24 and transfers the carrier CR to one ofthe heat treatment apparatuses 10, 12, 14, and 16 and the stocker 18.Thereafter, the carrier liner 22 causes the first and second arms 84 and84 to extend and transfer the carrier CR to an upper portion of acarrier load/unload portion GW of the apparatus or unit. Thereafter, thecarrier liner 22 causes the air cylinder 110 to place the arms 84 and 88and the carrier CR in flat position. Next, the carrier liner 22 causesthe air cylinder 72 to lower the carrier CR to the carrier load/unloadportion GW (see FIG. 12). Thus, since the carrier liner 22 transfers acarrier CR while wafers W contained therein are inclined by a properangle, the wafers W come in contact with the wall surfaces of thecarrier CR, thereby preventing the wafers W from shaking in the carrierCR. Therefore, the occurrence of dust in the carrier CR can besuppressed.

It should be noted that the drive mechanism which horizontally travelsthe carrier liner 22 along the transfer path 24 may be a conventionaldrive mechanism using a ball screw or a belt.

FIG. 8 shows peripheral portions of a transfer means (comprising thecarrier liner 22 and the transfer path 24) of a clean room mechanism.

A hanging partition wall 122 mounted on a ceiling 120 partitions a cleanroom into a treatment room 124 and a work room 126.

In the work room 126, HEPA filters 128 are dispersively disposed on theceiling 120. A grated panel 132 having a large number of ventilationholes is disposed on a floor 130. An air conditioner (not shown)supplies air to a supply chamber 134. Air flows through the HEPA filters128 which purify air. The purified air flows downward to the work room126 as a down flow. Thereafter, the air flows from the ventilation holeson the grated panel 132 to a return chamber 136 disposed between thegrated panel 132 and the floor 130. In the work room 126, thecleanliness of air therein is maintained to, for example, class 100. Inthis work room 126, a worker 135 operates a control unit (not shown).

In the treatment room 124, the heat treatment apparatuses 10, 12, 14,and 16, the stocker 18, and the I/O station 20 which construct the heattreatment system are spaced apart from the floor 130 by a predetermineddistance. HEPA filters 128 are also dispersively disposed on the ceiling120 of the treatment room 124. An air blowing fan 138 and a HEPA filter140 are disposed at an upper portion on the front side of each of theheat treatment apparatuses 10, 12, 14, and 16, and the stocker 18. Thetransfer path 24 is isolated from the work room 126 by an anti-staticdoor 142. The anti-static door 142 is made of vinyl chloride. Thetransfer path 24 is also isolated from the treatment room 124 by ananti-static door 142. The transfer path 24 is disposed in a transferchamber 300 partitioned off by anti-static doors 142 and 301. A bottomsurface 24a of the transfer path 24 has a plurality of ventilationholes. The transfer path 24 is connected to a duct 144 defined at abottom portion of the system through the ventilation holes. The duct 144and the work room 126 are partitioned off by a wall plate 146. An airintake fan 148 is disposed at a rear end portion of the duct 144.

Part of the purified air flows through the HEPA filter 128 to thetreatment room 124. Then, the air flows to the air blowing fan 138through an air intake opening 149 defined on the upper surface on thefront of each of the heat treatment apparatuses 10, 12, 14, and 16, andthe stocker 18. The air blowing fan 138 blows air to the HEPA filter140. Thus, more purified air flows to the transfer path 24. The purifiedair flows to the duct 144 through the ventilation holes on the bottomsurface 24a of the transfer path 24. The air blowing fan 148 disposed onthe ear end portion of the duct 144 blows the air to the treatment room124. Thereafter, the air flows to a return chamber (not shown). Thecleanliness of the treatment room 124 is maintained to, for example,around class 10000. An external carrier transfer robot which loads orunloads a carrier CR to or from the I/O station 20 performs a transferoperation in the treatment room 124.

In the heat treatment system according to the embodiment, the transfermeans comprising the carrier liner 22 and the transfer path 24 ispartitioned off from the work room 126 and the treatment room 124. Inaddition, purified air downwardly flows to the transfer means. Thus, thepurified air lets dust which takes place in a mechanical portion of thecarrier liner 22 flow to the duct 144 on the floor side. As a result,the transfer means can be isolated from particles from the work room126. Moreover, particles from the carrier liner 22 and the transfer path24 can be effectively suppressed.

In the above-described embodiment, the transfer means having the carrierliner 22 and the transfer path 24 is disposed in the transfer chamber300, which is partitioned off from the treatment room 124 and the workroom 126 by the anti-static doors 142 and 301. Alternatively, thetransfer chamber 300 partitioned by the anti-static doors 142 and 301may be airtightly sealed. In this case, an inert gas supply pipe 170 andan exhaust pipe 172 are connected to the transfer chamber 300. An inertgas (for example, N₂ gas) is supplied from the inert gas supply pipe 170to the transfer chamber 300. In addition, the inert gas is periodicallyexhausted from the exhaust pipe 172. As a result, the interior of thetransfer chamber 300 can be always maintained in an inert gasatmosphere.

As with the case shown in FIG. 9 (which will be described later), theinert gas supply pipe 170 and the exhaust pipe 172 shown in FIG. 8 areconnected to open/close devices 174 and 176. These open/close devices174 and 176 are adjusted by a stocker control device 178 in accordancewith signals inputted from an O₂ concentration detector 180 disposed inthe transfer chamber 300.

Next, the function of the stocker 18 according to the embodiment will bedescribed. As shown in FIG. 1, the carrier load/unload portion GW isdisposed on the front of the stocker 18. A plurality of (for example,five) first carrier storage chambers 18A are vertically staged behindthe carrier load/unload portion GW. A carrier elevator 18B is disposedbetween the carrier load/unload portion GW and the first carrier storagechambers 18A. A rear chamber 19 is disposed behind the stocker 18. Therear chamber 19 contains a purge mechanism and so forth which will bedescribed later.

In the stocker 18, a carrier CR has two orientations. When a carrier CRis loaded or unloaded to or from the carrier liner 22, the flangeportions FL thereof are oriented upward so that wafers W containedtherein are placed in upright position. On the other hand, when acarrier CR is stored in a first carrier storage chamber 18A, the flangeportions FL thereof are oriented sideward so that wafers W containedtherein are placed in flat position. The carrier load/unload portion GWis provided with a carrier orientation changing mechanism. The carrierelevator 18B is provided with a transfer arm (not shown) which loads orunloads a carrier CR to or from each of the first carrier storagechambers 18A.

FIGS. 9 and 10 show the first carrier storage chambers 18A of thestocker 18. As shown in FIGS. 9 and 10, each of the first carrierstorage chambers 18A has a box-shaped storage chamber main body 150 anda planar door 152. The top, bottom, both sides, and rear of the storagechamber main body 150 are closed with plates, whereas the front thereofis open. The planar door 152 opens or closes the front of the storagechamber main body 150. On each side of the storage chamber main body150, a bracket-shaped guide 154 is vertically disposed. Thebracket-shaped guide 154 slidably holds a side edge portions of the door152. One end of a cable 158 which supports the weight of the door 152 issecured to an upper edge portion thereof. The other end of the cable 158is wound around a reel 160 through guide rollers 162. The reel 160 isdisposed at a rear portion of the storage chamber main body 150, whereasthe guide rollers 162 are disposed between the reel 160 and the upperedge of the guide 154. An air cylinder 164 and a cylindrical linearguide 166 are disposed on each side of the storage chamber main body150. The air cylinder 164 and the linear guide 166 open and close thedoor 152. A guide rod 169 passes through a piston rod 168 of the aircylinder 164. Another guide rod 169 passes through the liner guide 166.These guide rods 169 are secured to the rear surface of the door guide154.

In FIG. 9, when the piston rod 168 of the air cylinder 164 on each sideof the storage chamber main body 150 extends to the door 152, the doorguide 154 and the door 152 extend together horizontally from the storagechamber main body 150. Thus, the lower surface of the door 152 isdisengaged from the lower edge on each side of the storage chamber mainbody 150. Next, the reel 160 is rotated in a predetermined direction soas to feed the cable 158. Thus, the door 152 drops by its dead weight.As a result, as shown in FIG. 10, the front of the storage chamber mainbody 150 is open. Thus, a carrier CR can be loaded or unloaded from thisopening. To close the door 152, the above-described operation isperformed in the reverse order. The lower surface of the door 152 isengaged with the lower edge on each side of the storage chamber mainbody 150. To airtightly close the door 152 of the storage chamber mainbody 150, a proper sealing material is preferably disposed on the frontsurface of the storage chamber main body 150.

As schematically shown in FIG. 11, the door 152 which is open in aparticular first carrier storage chamber 18A moves ahead of the door 152of the just lower adjacent first carrier storage chamber 18A. Since thecarrier transfer arm of the carrier elevator 18B accesses only onecarrier storage chamber 18A at a time, the door 152 of the just lowerfirst carrier storage chamber 18A is closed. Thus, the door 152 of thejust upper adjacent first carrier storage chamber 18A does not interferewith the just lower first carrier storage chamber 18A. As a result, theabove-described door open/close mechanism allows the installation spaceof the plurality of first carrier storage chambers 18A vertically stagedto be reduced. Therefore, the size of the stocker 18 can be reduced.

The stocker 18 is provided with a purge mechanism. The purge mechanismpurges the inside of each first carrier storage chamber 18 of a gastherein by using an inert gas so as to prevent wafers W contained in acarrier CR from being oxidized. As shown in FIG. 9, each first carrierstorage chamber 18A is connected to the inert gas supply pipe 170 andthe exhaust pipe 172. The inert gas supply pipe 170 and the exhaust pipe172 are provided with the open/close devices 174 and 176, respectively.As shown in FIG. 14, the open/close device 174 comprises an orifice 174aand an open/close valve 174b which is disposed in parallel therewith.The open/close device 176 comprises an orifice 176a and an open/closevalve 176b which is disposed in parallel therewith. Each of theopen/close valves 174b and 176b is a solenoid valve which is turned onand off by the stocker control device 178. Each first carrier storagechamber 18A is provided with an O₂ sensor which detects theconcentration of O₂ gas within the first carrier storage chamber 18A. AnO₂ concentration detector 180 is disposed outside the first carrierstorage chamber 18A. The O₂ concentration detector 180 detects an O₂concentration value corresponding to an output signal of the O₂ sensor.The O₂ concentration value is sent to the stocker control device 178.

When a carrier CR is loaded or unloaded, if the concentration of O₂ ineach first carrier storage chamber 18A exceeds a predetermined value,the stocker control device 178 turns on the open/close valves 174b and176b. Thus, an inert gas (for example, N₂ gas) supplied from an inertgas supply source 250 is supplied to the first carrier storage chamber18A through the gas supply pipe 170. The flow rate of the inert gas is,for example, 1 litter/min. Thus, an O₂ gas and a H₂ O gas in the firstcarrier storage chamber 18A are exhausted along with the inert gas tothe exhaust pipe 172. When the concentration of the O₂ gas in the firstcarrier storage chamber 18A decreases to the predetermined value orbelow, the stocker control device 178 turns off both the open/closevalves 174b and 176b.

As shown in FIG. 9, one end of the exhaust pipe 172 is connected to thefirst carrier storage chamber 18A, while the other end thereof is opento the outside. The length of the exhaust pipe 172 is in the range from1 to 10 m (for example, approximately 5 m). The open/close devices 174and 176 have variable orifices 174a and 176a, respectively, which areused for mass flow meters, flow meters, or the like. Thus, when theconcentration of the O₂ gas decreases to the predetermined value, theopen/close valves 174b and 176b are opened and small amount of the N₂gas is supplied so as to maintain the concentration of the O₂ gas in thefirst carrier storage chamber 18A. Thus, the consumption of N₂ gas isreduced. In addition, the increase of inner pressure is prevented.

As described above, in the stocker 18 according to this embodiment, eachfirst carrier storage chamber 18A is purged of unnecessary gases such asO₂ gas and H₂ O gas by using an inert gas. The purged gases areexhausted to the outside of the carrier storage chamber 18A. Thus, thewafers W contained in a carrier CR can be protected from being oxidizedor deteriorated. As a result, since the wafers W which are free from anatural oxide film are transferred from the stocker 18 to each of theheat treatment apparatus 10, 12, 14, and 16, the wafers W can beproperly heat-treated.

In the above-described embodiment, an inert gas was suppliedcorresponding to the atmospheric gases in each first carrier storagechamber 18A by using the O₂ concentration detector 180, the open/closevalves 170 and 172b, and so forth. Alternatively, the inert gas may beintermittently or continuously supplied at a proper pressure and aproper flow rate.

FIG. 12 shows an example of each of the heat treatment apparatuses 10,12, 14, and 16. Each heat treatment apparatus has a treatment chamber310 which can be air-tightly constructed. An opening 311 is formed onone side of the treatment chamber 310. A carrier CR is loaded to orunloaded from the opening 311. A wafer load/unload portion GW disposedon the front of the apparatus is provided with a carrier orientationchanging portion 190. The carrier orientation changing portion 190rotates the carrier CR by 90° so as to change the orientation thereofbetween a first orientation in which the flange portions FL are orientedupward and a second orientation in which the flanges portion FL areoriented sideway. In the first orientation, wafers W contained in thecarrier CR are placed in upright position. In the second orientation,the wafers W contained in the carrier CR are placed nearly in flatposition.

The treatment chamber 310 houses a heating furnace 206, a plurality of(for example, four) second carrier storage chambers 196, and a transferstage 194. The heating furnace 206 heat-treats wafers W contained in acarrier CR. Each of the second carrier storage chamber 196 airtightlystores a carrier CR. The second carrier storage chambers 196 arevertically staged. A carrier elevator 192 is vertically disposedadjacent to the wafer load/unload portion GW in the treatment chamber310. A carrier transfer 198 is disposed on the carrier elevator 192. Thecarrier transfer 198 transfers a carrier CR among the wafer load/unloadportion GW, the transfer stage 194, and the second carrier storagechambers 196. A wafer transfer 202 is disposed behind the transfer stage194. The wafer transfer 202 transfers the wagers W between a carrier CRon the transfer stage 194 and a wafer boat 200 disposed below theheating furnace 206. The wafer transfer 202 is disposed on a waferelevator 315. The wafer boat 200 is loaded to or unloaded from theheating furnace 206 by the boat elevator 204.

An inert gas supply pipe 170 and an exhaust pipe 172 are connected tothe treatment chamber 310 which is air-tightly constructed. As with thecase shown in FIG. 9, the inert gas supply pipe 170 and the exhaust pipe172 are connected to the open/close devices 174 and 176, respectively.The open/close devices 174 and 176 are controlled by the stocker controldevice 178 corresponding to signals inputted from an O₂ concentrationdetector 180 disposed in the treatment chamber 310.

As described above, the four second carrier storage chambers 196 whichare air-tightly constructed are vertically staged. A holding shelf 316is disposed within each of the second carrier storage chambers 196. Theholding shelf 316 supports a carrier CR. The second carrier storagechamber 196 temporarily stores a carrier CR which contains the rowwafers or the treated wafers. One side of each second carrier storagechamber 196 is open. This side faces the carrier elevator 192. As withthe case shown in FIG. 9, the opening of each second carrier storagechamber is closed by a door 154 held by a pair of guides 154.

As described above, an inert gas supply pipe 170 and an exhaust pipe 172are connected to each of the second carrier storage chambers 196. Aswith the case shown in FIG. 9, the inert gas supply pipe 170 and theexhaust pipe 172 are connected to open/close devices 174 and 176,respectively. The open/close devices 174 and 176 are adjusted by thestocker control device 178 corresponding to signals inputted from an O₂concentration detector 180 disposed in each of the second carrierstorage chambers 196.

In the above-described embodiment, the treatment chamber 310 and thesecond carrier storage chambers 196 were air-tightly constructed. Inaddition, the inert gas supply pipe 170 and the exhaust pipe 172 areconnected to each of the treatment chamber 310 and the second carrierstorage chambers 196. However, either the treatment chamber 310 or thesecond carrier storage chambers 196 may be air-tightly constructed. Theinert gas supply pipe 170 and the exhaust pipe 172 may be connected tothe chamber(s) which is airtightly constructed.

FIG. 13 shows the construction of a control system of the heat treatmentsystem. In this heat treatment system, treatment apparatus controlportions 210 and a controller 212, which are local controllers 212, areconnected to a host computer in parallel. The treatment apparatuscontrol portions 210 control each portion of the heat treatmentapparatuses 10, 12, 14, and 16. The controller 212 controls theoperation of each portion of the stocker 18, the I/O station 20, and thecarrier liner 22.

The controller 212 controls the first and second carrier transferportions 30 and 46 at the I/O station 20 so that they transfer androtate carriers CR between the first and second carrier load/unloadpositions 20a and 20b. In addition, the controller 212 exchanges signalswith an external transfer robot through an optical communication portion21. Moreover, the controller 212 causes a stocker control device 216(equivalent to the stocker control device 178 shown in FIG. 9) tocontrol each portion of the stocker 18 (such as a carrier transfermechanism 218, a carrier orientation changing mechanism 220, a dooropen/close mechanism 222, a N₂ supply mechanism 224, and an exhaustmechanism 226).

Furthermore, the controller 212 causes a carrier liner control portion228 to control each portion of the carrier liner 22 (such as ahorizontal traveling mechanism 230, a carrier elevator mechanism 234, anarm expansion/retreat mechanism 235, a carrier inclination mechanism236, and an arm open/close mechanism 238).

The above-described embodiment was the heat treatment system comprisingthe upright type heat treatment apparatuses. However, the presentinvention is not limited to such a system. Alternatively, the presentinvention can be applied to other type heat treatment systems.Generally, the present invention may be applied to any treatment systemwhich transfers a carrier which contains planar workpieces such aswafers and LCD substrates.

As described above, according to the treatment system of the presentinvention, since carriers are stored in carrier storage chambers whichare airtightly constructed and the carrier storage chambers are purgedof gases therein by using an inert gas, the workpieces contained in thecarriers can be prevented from being oxidized and deteriorated.

Although the present invention has been shown and described with respectto a best mode embodiment thereof, it should be understood by thoseskilled in the art that the foregoing and various other changes,omissions, and additions in the form and detail thereof may be madetherein without departing from the spirit and scope of the presentinvention.

What is claimed is:
 1. A treatment apparatus for performing a predetermined treatment on a planar workpiece contained in a carrier, said apparatus comprising:a first air-tight carrier storage chamber for storing a carrier; gas supply means for supplying an inert gas to said first carrier storage chamber, said gas supply means including a gas supply source, an inert gas supply pipe for connecting said gas supply source and said first carrier storage chamber, and a gas supply valve device; gas exhaust means for exhausting a gas from said first carrier storage chamber, said gas exhaust means including an exhaust pipe having a first end and a second end, said first end being connected to said first carrier chamber, said second end being open and a gas exhaust valve device; an oxygen concentration detector connected to said first carrier storage chamber; and a control device connected to said oxygen concentration detector, said control device being adapted for adjusting said gas supply valve device and said gas exhaust valve device.
 2. A treatment apparatus for performing a predetermined treatment on a planar workpiece contained in a carrier, said apparatus comprising:a first air-tight carrier storage chamber for storing a carrier; gas supply means for supplying an inert gas to said first carrier storage chamber; gas exhaust means for exhausting a gas to said first carrier storage chamber, wherein said first carrier storage chamber has an opening, a pair of guides vertically disposed at side edge portions of said opening, and a planar door that is vertically slidably disposed between said pair of guides, said planar door being adapted to open and close said opening.
 3. A treatment system, comprising:a treatment apparatus for performing a predetermined treatment for a planar workpiece contained in a carrier; a first carrier storage chamber for storing a carrier; transfer means, disposed between said treatment apparatus and said first carrier storage chamber, for transferring a carrier therebetween, said transfer means further being disposed in an air-tight transfer chamber; gas supply means including a gas supply source, a gas supply pipe for connecting said gas supply source and said first carrier storage chamber, and a gas supply valve device; gas exhaust means including an exhaust pipe having a first end and a second end, said first end being connected to said first carrier storage chamber and said second end being open, and a gas exhaust valve device; an oxygen concentration detector connected to said first carrier storage chamber; and a control device connected to said oxygen concentration detector, said control device being adapted for adjusting said gas supply valve device and said gas exhaust valve device.
 4. A treatment apparatus for performing a predetermined treatment for a planar workpiece contained in a carrier, said treatment apparatus comprising:a treatment chamber; a furnace disposed in said treatment chamber and adapted for heat-treating a workpiece contained in a carrier; an air-tight carrier storage chamber disposed in said treatment chamber adapted for storing a carrier, said carrier storage chamber having an open portion with a pair of guides vertically disposed at side edge portions thereof and a planar door vertically slidably disposed between said pair of guides, said planar door being adapted to open and close said open portion; gas supply means for supplying an inert gas to said carrier storage chamber; and gas exhaust means for exhausting gas from said carrier storage chamber.
 5. A treatment apparatus for performing a predetermined treatment for at least one planar workpiece contained in a carrier, said treatment apparatus comprising:a treatment chamber; a furnace disposed in said treatment chamber and adapted for heat-treating workpieces contained in a carrier; an air-tight carrier storage chamber disposed in said treatment chamber and adapted for storing a carrier; gas supply means for supplying an inert gas to said carrier storage chamber, said gas supply means including a gas supply source, an inert gas supply pipe for connecting said gas supply source and said carrier chamber, and a valve device disposed on said inert gas supply pipe, and gas exhaust means for exhausting a gas from said carrier storage chamber said gas exhaust means including an exhaust pipe having a first end and a second end, said first end being connected to said carrier chamber, said second end being open, and a valve device disposed on said exhaust pipe, an oxygen concentration detector connected to said second carrier storage chamber, and a control device connected to said oxygen concentration detector, said control device being adapted for adjusting said valve device of said gas supply means and said valve device of said exhaust means.
 6. The treatment apparatus according to claim 5 further comprising transfer means for transferring said carrier.
 7. A treatment apparatus for performing a predetermined treatment for a planar workpiece contained in a carrier, said treatment apparatus comprising:an air-tight treatment chamber; a furnace disposed in said treatment chamber, said furnace being adapted for heat-treating a workpiece contained in a carrier; a carrier storage chamber disposed in said treatment chamber and adapted for storing a carrier; gas supply means for supplying an inert gas to said air-tight treatment chamber, said gas supply means including a gas supply source, an inert gas supply pipe for connecting said gas supply source and said treatment chamber, and a gas supply valve device disposed on said inert gas supply pipe; gas exhaust means for exhausting a gas from said treatment chamber, said gas exhaust means including an exhaust pipe having a first end, a second end, and exhaust gas valve device, said first end being connected to said treatment chamber, said second end being open; an oxygen concentration detector connected to said carrier storage chamber: and a control device connected to said oxygen concentration detector, said control device being adapted to adjust said gas supply valve device and said gas exhaust valve device.
 8. The treatment apparatus according to claim 7 further comprising transfer means for transferring said carrier. 